FIG. 7.

LTD4, not LTB4, enhanced E. coli K1 penetration into the brain in cPLA₂α^−/− mice. Bacterial counts in blood (CFU per milliliter) (A), brain (CFU per gram) (B), and kidney and spleen (CFU per gram) (C) were determined at 1 h after intravenous injection of E. coli K1 strain RS218. (A to C) LTD4 or LTB4 (500 ng in 100 μl PBS) was injected through the tail vein 10 min before bacterial injection. Data shown are means ± SEM (n = 4). *, P < 0.05 (Student's t test, compared to the vector control [5% ethanol]). (D) LTD4 or LTB4 did not affect the blood-brain barrier permeability in cPLA₂α^−/− mice. Evans blue dye extravasation into the brain tissue was used as an indicator of the blood-brain barrier permeability. Evans blue extravasation was expressed as micrograms per milligram of brain protein. Data shown are means ± SEM (n = 4).